Connecting device for a multilayer flat element equipped with electrical functional elements and flat element

ABSTRACT

A connector for a flat multilayer element that includes a first rigid glazing pane provided with one or more electrical functional elements and a second rigid glazing pane joined flat to that side of the first rigid glazing pane that is provided with the functional elements. The second pane has at least one cutout for making an electrical connection to the functional elements. A liner is fastened in the cutout by a projection, the edge of which lies in the plane between the two rigid panes and/or catches, via the rear, on an undercut of the cutout. The liner serves as a counterbearing surface for fastening at least one connection piece electrically connected to the functional elements.

The invention relates to a connector for a flat multilayer element thatcomprises a first rigid glazing pane provided with one or moreelectrical functional elements and a second rigid glazing pane joinedflat to that side of the first rigid glazing pane that is provided withthe functional elements, this second pane having at least one cutout formaking an electrical connection to the functional elements.

The invention also relates to a flat element equipped with such aconnector.

It is generally known that systems based on thin electrically conductinglayers may be use as resistance heating elements by applying anelectrical voltage. There are many applications of this technique bothin the automobile sector and in the building sector.

In general, these multilayer systems deposited on flat substrates, forexample window glazing, comprise at least one metal layer, for examplemade of silver, and (for transparent multilayer systems) dielectriclayers on both sides of the silver layer and, optionally, also blockinglayers made of various materials, and among these also covering layersfor increasing the mechanical strength capability of the multilayerstructure. In many cases, the infrared radiation reflection propertiesof multilayer systems are also used as thermal insulation.

To establish a uniform current density in these multilayer systems usedas heating layers is usually a problem. It is necessary above all toprevent areas being locally overheated by high current densities, calledhot spots. To achieve this, and in many applications, the heating layeris provided with plane electrodes in the form of a ribbon. They consist,for example, of thin metal ribbons deposited or attractively colored andelectrically conducting, which are printed and optionally baked, andthey allow the current to be introduced and removed over as wide a baseas possible. However, in most cases, these connections do not meetoptical/esthetic requirements and must consequently be masked. Since inmany applications, for example for vehicle windows, they are mostlylocated along the edge of the substrate, they can be produced withlittle workmanship.

It is also known, in such heating layers, how to vary the flow anddistribution of the current by means of fine lines that divide theheating layer into individual current paths or sections electricallyconnected in parallel to one another, and the ohmic resistances of whichare if possible all the same.

German patent application 10208552.8 discloses a plate element providedwith an electrically conductive coating (“heating layer”) that issuitable for being connected directly to the voltages of the usual mainsin the domestic field. It is essentially formed from a multilayercomposite structure that comprises a first rigid pane, with the heatinglayer deposited on it and an adhesive layer, and a second rigid pane. Inthe electrical connection region of the heating layer, the second rigidplane is provided with a bore. In this bore, two regions of differentpolarity of the heating layer are located in close proximity. Providedin each of these regions is an electrode applied to the heating layer,to which electrode a current lead is joined by soft solder. The currentflow between the two connection terminals belonging to the same heatinglayer is guided, as already mentioned, by dividing up the heating layerby means of fine lines.

DE-U1-20 107 908 discloses a connector in which a glazing unit coated soas to be electrically conducting is provided with retaining elementsthat are in the form of clamping fittings serving at the same time assupports for electrical contacts. Resilient tabs incorporated into theclamping fittings are applied so as to be electrically conducting on thecoating of the glazing unit and pressed against the latter.

In another context, DE-A1-19 958 879 discloses an insulating glazingunit provided with a composite glass pane, the adherent layer of whichincludes functional elements (solar cells). These electrical connectionconductors are each passed through a cutout made in one of the panes ofthe composite and in the opposite rigid pane of the insulating glass,that region of this penetration into the intermediate space of theinsulating glass between these panes being surrounded by a spacer ofannular shape. The conductors may also be passed through a hollow pin ofa point support that is used for fastening the insulating glazing unitto a subjacent structure.

In the field of fittings and fastenings for composite glazing units,DE-A1-3 908 983, DE C2-4 325 024 and DE-U1-8 701 693 teach the techniqueconsisting in providing, in the rigid pane, cutouts into which thefastening elements may be inserted and fastened. These fasteningelements may have projections in the form of a radial flange whichextend into the adhesive layer of the composite and which, when theassembly is completed, engage via the rear in the glazing unit. Theircutouts may optionally have an undercut. In the latter case,undercut-engaging pegs are also described for composite glass fastenings(DE-A1-3 811 249). The surface of the other side of these compositeglazing units each time remains entirely intact. The last mentionedsources do not concern electrical connectors. The objective of theinvention is to further improve a connector of the type indicated at thebeginning and to create a flat element equipped therewith.

According to the invention, this objective is achieved in that a lineris fastened in the cutout of the rigid pane by a projection, the edge ofwhich lies in the plane between the two rigid panes and/or catches, viathe rear, on an undercut of the cutout, and in that the liner serves asa counterbearing surface for fastening at least one connection pieceelectrically connected to the functional elements. Moreover, a flatelement is equipped with electrical functional elements incorporatedbetween two rigid plates and at least one connector according to theinvention. The features of the independent claims and of the dependentclaims that are associated with the connector and with the flat elementgive advantageous developments of these subject matters.

According to the invention, a liner is placed in the cutout of one ofthe rigid panes and serves as a counterbearing surface for fastening atleast one connection element electrically connected to the functionalelement. This liner possesses or forms a “radial” projection which bygeometrical complementarity is anchored into the cutout.

As electrical functional elements, heating elements are especiallyenvisioned, particularly heating layers, but also sensors and solarelements, which each time are incorporated into a multilayer structureand have to be brought into electrical contact with the outside. Asregards the structure described here of the connector or of the liner,the function of the elements that must finally be connected is ofsecondary importance.

The functional elements may in this case be placed either on that rigidpane with the cutout or on the rigid pane facing the latter. It is alsopossible to envision constructions in which both panes are provided withelectrical functional elements, for example electrodes forelectroluminescent lighting elements or solar cells, and are equippedwith one or more connectors according to the invention.

The edge of the cutout can catch, via the rear, on said projection ofthe liner in the plane lying between the two rigid panes (the plane ofthe adhesive layer). This liner will then be fastened in the cutoutbefore the glazing assembly is manufactured in such a way that theprojection can be incorporated into the adhesive layer. The thickness ofthe projection will therefore be less than the thickness of the adhesivelayer.

The projection may also engage behind a rear layer or bevel of thecutout, located inside the composite. This may be produced in a mannerknown per se by a liner made of several parts, the individual parts ofwhich are placed together in the actual cutout. However, it is alsopossible to use, as liner, an appropriate undercut-engaging peg thatforms said projection only when it has been passed into the cutout andclamped therein. The two variants may be installed advantageously afterthe manufacture of the glazing assembly.

Particularly preferably, the liner may be used as base for a point ofcollection of all the electrical interface functions of the flatelement.

It then forms the base of the actual electrical connection contactswhich are preferably configured as spring contacts. For applicationsprincipally intended in a flat heating element, the working voltages ofwhich are relatively high, only a low (AC) current has to betransferred; likewise, the heating elements used in buildings are as ageneral rule not exposed to any vibration. Thus, no corrosion problemsshould be expected which, in other fields of use (construction ofvehicles) may have the effect of degrading the contact by high transferresistances. In addition, should it be necessary, the contact region maybe hermetically sealed in such a way that moisture and dirt cannotpenetrate.

Should it be necessary, the electrical contacts with the functionalelements or their electrodes may, however, also be produced by softsoldering or protected only as a supplement. Soft soldering techniquesare known that allow these soldering locations to be reliably meltedwithout direct contact with the heat source (induction soldering orlaser soldering) and can be used even through the coated pane withoutdestroying the coating.

The liner may serve as base for a connector plug by means of which aconnecting conductor of the functional elements may be electricallyconnected. However, it is obvious that a fixed connecting conductor mayalso be provided, said conductor emerging from a connector casing thatis fastened to the liner and optionally has a plug on the end of it.

In another preferred variant, at least one switching member, for turningthe functional elements on and off, is provided in the region of theliner. In the use as “flat heating element”, this switching member may,in another advantageous variant, be controlled by at least onetemperature probe that detects the actual temperature of the heatinglayer in the connection region. Since the highest current densitiescould occur in this region of the local electrical power supply, atleast one temperature probe will be placed therein.

These temperature probes may even be also produced as current limiters(for example cold conductors whose ohmic/electrical resistance increaseswhen the temperature increases), thereby making it possible to dispensewith said switching member if an appropriate characteristic line isprovided. Optionally, it is also possible to provide an electricalprotection device that electrically protects the functional element inquestion.

In yet another advantageous embodiment, the liner may also form the baseof a device for evaluating or receiving the control signals by means ofwhich a surface heating element/functional element may be individuallyaddressed by a remote control and be connected and disconnected. In thecase of a heater, these control signals are created, for example, bymeans of room thermostats and temperature probes. They may betransmitted by special conductors or by the supply conductors alreadyprovided as bus conductors. In the latter case, coded control pulses aresuperimposed on the supply voltage or the mains voltage, and may beelectronically filtered in the connector of the surface heating elementin question. However, the control signals are preferably transmitted byradio, infrared, etc. and, in the region of the connector, anappropriate receiver and decoder, in addition to the switching orcontrol members connected downstream, will be provided.

Complementarily, the liner may be used as base for a manually adjustabletemperature limit which makes it possible, with priority over theinternal temperature probe optionally provided, to define a maximumelectrical power consumed and therefore the maximum effectivetemperature of the flat heating element, below the absolute maximumtemperature preset in the factory of the flat heating element inquestion.

In one particularly preferred embodiment, as many as possible of all thenecessary components will be miniaturized (for example in the form of amicrochip or a microprocessor) and brought together in a connection boxor case that may be fastened with little workmanship required onto saidliner. Screws may be provided for the connection. However, it would alsobe possible to provide a snap-fit (releasable) connection if thenecessary sealing of the contact region can thus be obtained.Optionally, an adhesively bonded connection between the liner and theconnection box could also be envisioned.

At the same time as fastening said connection box, it is also possibleto connect the electrical (spring) contacts to the functional elements.This has the advantage, on the one hand, of not exceeding a predefinedproof pressure on the contacts and, on the other hand, when optionallyreleasing and removing the connection box subsequently, for the purposeof maintenance or repair, of also deactivating the functional elements,by disconnecting them from the current or electrically.

All of the active elements of the connector may, optionally afterappropriately adapting the voltage level, be electrically supplied withan operating voltage optionally applied as such to the functionalelements. However, it would also be possible to supply them autonomouslyusing batteries that will be placed in the connection box.

It is also possible to provide in the connection region, with littleworkmanship required, operational indicators for checking whether thefunctional elements are connected, activated or ready to operate (onstandby). When the flat element is transparent, these displays may belight signals, the light from which passes through the flat element. Itis therefore obvious that they shall not be covered by opaque masks orthe like, or that appropriate observation windows shall be provided insuch a mask.

In all the differences between the connector described here and thepoint fastening elements normally used for plates (of glass), it ispossible to imagine using a connection point that has the featuresdescribed here also as fastening points for the flat element when thefastening element can be adapted to the imposed conditions as regardselectrical standpoint and when it can be mounted on a subjacentstructure. The latter may, for example, have devices for suspending theflat element or elements, which devices correspond to appropriatecounter-supports provided on the connection box that will be configuredso as to have the appropriate stability. Otherwise, the flat elementwill be fastened in its mounting position by other suitable means thatengage for example its edge (for example, frames, retention clips), orwill also be incorporated edgewise into a wall or window facade.

The connector according to the invention may be advantageously installedpractically anywhere on the surface of the flat element, whether nearits edge or in the central region. It is obvious that, should it benecessary, several of these connectors may be provided on the same flatelement, for example if several heating fields or solar cell modulescapable of operating independently have to be connected.

When positioning the connector for a flat heating element, therequirement to have as uniform as possible a current density in theheating layer to be supplied remains an essential parameter, and thismay entail certain restrictions on the choice of location of theconnector.

Further details and advantages of the subject of the invention willbecome apparent from the drawing of examples of embodiments of aconnector for a flat heating element and from the following detaileddescription of them.

In the simplified representations, not drawn to scale:

FIG. 1 shows an overall perspective view of a flat heating element witha connector according to the invention;

FIG. 2 shows a view of the connection region with a liner inserted forfastening the connector;

FIG. 3 shows a sectional view on the line III-III of FIG. 1 of a firstembodiment of the connector;

FIG. 4 shows a sectional view, corresponding to that of FIG. 3, of asecond embodiment of the connector according to the invention; and

FIG. 5 shows another sectional view corresponding to FIG. 3 of a thirdembodiment of the connection according to the invention.

In FIG. 1, a flat heating element 1 is produced in the form of a glazingassembly provided with a first rigid pane 2, with an interlayer 3 andwith a second rigid pane 4. The first rigid pane 2 is preferably athermally prestressed glass provided on its surface facing theinterlayer 3 with a heating layer 5 configured as an electricallyconductive coating. The heating layer 5 is formed from a compositionand/or from a succession of layers suitable for operation as a flatheating layer and which can be thermally stressed sufficiently forprestressing the pane. Suitable multilayer systems have been describedmany times in the prior art so it is unnecessary to go into furtherdetails about them. They may be manufactured with a high transmissionfor visible light and therefore with the aim of being transparent.

Suitable arrangements ensure that said coating 5 is passivated at theperiphery, along the edge of the flat heating element 1, that is to saythere is neither an electrically conducting contact near its external orfront surface nor any risk of the multilayer material being corroded bythis external environment. For example, it is possible to provide in thecoating 5, a short distance from the outer edge of the flat heatingelement 1, a continuous peripheral separating line that fulfills thesetwo functions. As a variant, it is also possible, in a known manner, tofree completely from the multilayer material, or to remove subsequently,a narrow peripheral strip along the edge of the flat heating element 1.In all cases, a hermetic seal is formed at the border interstice usingthe synthetic thermoplastic adhesive material that forms the interlayer3 (for example polyvinyl butyral (PVB) or ethylene/vinyl acetate (EVA)).It will be understood that the material of the interlayer must beselected so as to be properly compatible with the material of thecoating 5.

FIG. 1 shows the essential components of the electrical power supply forthe heating layer 5, namely firstly two plane electrodes 6 in the formof a ribbon, which are placed on both sides of a line of separation 7that isolates the two poles of the heating layer 5 from each other. Thecurrent flows between the two electrodes in a manner predetermined bythe structural lines made in the heating layer and as is clearlyapparent from the drawing. A connection box 8 provided with a connectingcable 9 (shown only in part) is fastened at the point of electricalcontact between the heating layer 5 and the pair of electrodes 6 to thesecond rigid pane. Particularly advantageously, all the electricalinterfaces and devices are brought together locally at one point on theflat heating element 1.

As a departure from the representation shown in FIG. 1, the electrodesmay of course have shapes other than that of a ribbon (for example asemicircle). Furthermore, it is possible for the structural lines tostart in the region of the heating layer that is covered by theelectrodes, in such a way that the electrode is brought into electricalcontact with several current paths electrically connected in parallel.Such a configuration or structuring of the heating layer alongside itsconnection region may above all be necessary when it would be impossiblefor the current supply to be near the edge, unlike what is shown.

FIG. 2 shows the electrical-connection region of the flat heatingelement in a plan view in which the connection box has been omitted. Thepane 4, which may again be made of glass (optionally prestressed) or ofsynthetic material, has a bore 11 into which a liner 12 in the form of abush is securely inserted. Its outer perimeter is matched as preciselyas possible to the diameter or perimeter of the bore 11. This liner 12catches behind the edge of the bore 11, in the plane of the interlayer3, by means of a flange projection 13, configured here as an annularshoulder. The open internal space of the liner 12 reveals the heatinglayer 5, the two electrodes 6 and the line of separation 7. The surfacesare shown by gray rectangular fields on which the electrical-connectioncontacts may be placed.

The liner 12 may include shaped elements that are used for fastening aconnector and for preventing it from rotating. In this embodimentexample, these are catches formed in the wall of its bore and areprovided with bores into which screws may be screwed. As a departurefrom the representation, these shaped elements may be placedunsymmetrically in order to allow the insertion of other components inthe correct position.

FIG. 3 shows a greater detail example of the structure of the electricalconnection device according to the invention, in cross section,identical parts being indicated by a different reference number than inFIGS. 1 and 2. The multilayer structure of the flat heating element maybe seen. The figure shows a portion of the thickness of the rigid pane2, and a double chain-link line passing through the rigid pane 4 alsoindicates that its thickness has been reduced as shown. It is obviousthat these two rigid panes may be much thicker than the interlayer 3. Inthe region of the electrodes 6 and of the connection box 8 (which isshown here only partly), their material has been removed in order toallow obstacle-free access to the electrodes 6. A defined amount ofmaterial has to be removed before the two rigid panes are joinedtogether by melting the interlayer 3, in such a way that the adhesivematerial cannot advance as far as the electrodes.

In the present representation, the diameter of the bore 11 has beenshown smaller than the thickness of the pane 4; it will be understoodthat the bore is dimensioned with a width sufficient for the type ofconnector provided each time.

Optical masking of the connection region is not necessary for itsoperation—it merely fulfills an esthetic function. In the mounted state,the pane 2, and therefore that side of the flat heating element notfacing a connector, will form its visible side. It is only by way ofexample that, in the connection region of the electrode 6, an opaquelayer 10 has been provided between the heating layer 5 and the glasssurface in order to mask this region from the outside. If necessary, itis also possible, of course, to obtain the same effect with other means,for example by bulk-tinting the rigid pane 2, by applying a decorationto its outer surface and/or by designing the heating layer itself as amirror, for example by omitting an non-reflecting layer on its sideclose to the surface.

Moreover, the actual electrodes may also be used as decorative elementsby being given a visually attractive appearance. It will then bepossible to dispense with the opaque layer 10.

As could already seen in FIG. 2, the bush-shaped liner 12 is fastened inthe bore 11 of the second rigid pane 4. It axial length correspondssubstantially to the thickness of the rigid pane 4 (a few millimeters)and it penetrates further into the plane of the interlayer 3. Itsprojection 13, extending as a radial flange toward the outside, engagesbehind the edge of the bore 11 in such a way that the liner 12 is heldtherein by shape complementarity and cannot be extracted therefrom.

As was pointed out above, this liner must be inserted into the bore 11before the two rigid panes 2 and 4 are joined together. It is only afterthe thermoplastic interlayer 3 has melted that the liner is fixeddefinitively. It may be seen in the drawing that the projection 13 isstill on top of the material of the interlayer.

The liner 12 forms the base of the connection box 8. Two verticalchain-linked lines denote a screwed connection between the two portions.Fastened in the bore of the liner 12 by the connection box 8 is asupport block 14 from which emerge two spring contacts 15 that extend asfar as the electrodes 6 and rest in an electrically conducting manner onthem. A temperature probe 16, indicated symbolically, is also held inplace by means of the contact block 14 and the liner 12 in contact withthe coated surface of the rigid pane 2. Said probe serves to detect theactual temperature in the contact region of the electrodes 6. Thesupport block 14 is inserted into the correct position, optionallyforce-fitted by suitable shaped elements, in the liner 12 in such a waythat the spring contacts 15 come into contact with the electrodeprovided each time, and is then immobilized. The support block may formwith the connection box 8 a fixed first unit and this may be fitted intothe liner 12 at the same time as said connection box.

Although in the intended use on a flat heating element 1 the springcontacts 5 meet the requirements for a reliable and durable electricalconnection, should it be necessary they could be soldered, in particularby suitably pretinning them, it being possible for the necessary heat tobe provided without any contact, for example through the coated pane 2.

The switching symbols of a switch 17 and a transistor 18 represent theelectrical or electronic equipment of the support block 14 or of theconnection box 8 and may each time represent a number of correspondingelements. Other control and switching functions are also assigned tothis region of the connector in addition to supplying the electricalvoltage of the power supply to the electrode 6 via the connection cables9.

A switching element has to assess the measurements by the temperatureprobe 16 and possibly disconnect, at least temporarily, the currentsupply to the heating layer should the actual temperature exceed apermissible threshold. However, it is also possible to provide aswitching element that protects against temperature overruns and, in amanner known per se, limits the consumed electrical power to acceptablevalues.

At least one switch, which may have an electronic or electromechanicalconfiguration, manages the supply of current to the heating layer. Thisswitch may be basically connected manually and locally, and becontrolled by sensors, for example the temperature probe 16, or by aremote control device. As already indicated, the latter may form part ofan automatic system for regulating the temperature of a room(air-conditioning plant, etc.), but may also, optionally andfundamentally, be manually controlled.

If the control signals are transmitted by radio, an appropriate receiverand a decoder and other switching means (for example amplifiers) willhave to be provided in the connection box 8 or in the support block 14.If the control signals are transmitted via conductors, it will benecessary to provide suitable evaluation members for this purpose, inparticular if control signals are transmitted via the conductors, whichare present in any case (cable 9), for connection to the mains and mustbe filtered in situ.

Not shown here are elements for displaying the operational status of theflat heating element 1. In a preferred variant, these display elementsmay be configured in the form of light signals (light-emitting diodes)and, for example, may be placed near the line of separation 7 betweenthe spring contacts 15 and beside the temperature probe 16 so that theycan be seen from outside of the rigid pane 2. They are also suppliedelectrically via the support block 14 and controlled by said switchingelements 17, 18.

After the connector has been manufactured and its operation checked, itis also possible, if necessary, to form a seal between the surface ofthe pane and the connection box 8 with a seal 19. As a departure fromwhat is shown, it is also possible, of course, to place this sealdirectly between the underside of the connection box 8 and the surfaceof the pane.

FIG. 4 shows, in a sectional view that corresponds to that of FIG. 3, avariant of a liner which in this case is used in an undercut bore 11′ inthe second rigid pane 4. Where this figure shows the same components asin FIG. 2, these bear the same reference numbers and will not beexplained further. The liner is made as two parts, namely with anundercut-engaging peg 12D and a bush screw 12S. Such undercut-engagingbushes are already known in many glass applications. The technique ofproducing undercut or recessed bores 11′ in glass panes is also a matureone.

The undercut-engaging peg 12D may be inserted from the outside into thebore 11′ after the assembly has been produced. The bush screw 12S, whichmay be made of metal or of a high-strength synthetic material, is thenscrewed in. Vertical lines along its outer edge indicate itsself-tapping external thread. As the screwing proceeds, theundercut-engaging peg 12D deforms as indicated into a projection 13′that extends radially as a flange. It may be seen that this projectionfills the undercut bevel of the bore 11′ with geometricalcomplementarity until it becomes impossible for it to be extractedaxially. Likewise, the bush screw 12S is immobilized radially andaxially in the bore by its external thread engaging in the peg.

The optional penetration of the undercut-engaging peg 12D into the planeof the interlayer does not result in excessive local stresses that couldhave the effect of locally delaminating or even breaking a pane. In caseof doubt, the material of the interlayer will be removed if it is notdeformable enough in the region of the bore 11′ over the distanceindicated, and hence up to approximately its edge, in such a way thatthe peg can expand freely in the plane of the interlayer.

The actual bush screw can also be screwed only as far as a predetermineddepth in order not to come into contact with the electrodes in thebottom of the bore 11′ or to damage the latter or the heating layer 5.It must also not touch the contact springs 15.

Unlike when fastening a load-bearing glass, in the present applicationone need not expect high forces to be acting, so the clamping force ofthe peg does not need to be particularly high. However, it may benecessary for the pane 4 to be also made of prestressed glass, and inthat case the bore 11′ will have to be made before the prestressingoperation.

In one particularly advantageous variant, the connection box 8 and thebush screw 12S may be combined into a fixed entity. The casing of theconnection box could then be used as a lever for screwing the bush screwin by hand, the underside of the connection box that has just beenplaced on the top side of the pane 4 at the edge of the bore 11′ thenforming a depth stop. In this unit, the support block may be fastened inthe correct position with the contact springs and optionally thetemperature probe.

Although, in both FIG. 3 and FIG. 4, the liner is practically flush withthe main surface of the rigid pane 4, the connection box projectsslightly above this surface. As this side of the flat heating element 1is not for the most part turned toward the observer/user in the mountedstate, but is possibly located so as to face a wall or is integratedinto the latter, the visibility of the connector on the mask (oroptionally on the opaque electrodes configured as decorative elements)remains on the one hand limited, and on the other hand there is inpractice no risk generated by unauthorized or inadvertent manipulationof the connector. If a handle is provided for actuating a control memberof the connector, this will, of course, preferably be placed at the mostaccessible points, for example near the edge of the flat heatingelement.

Although with regard to FIG. 4 reference was made only to anundercut-engaging peg for the “undercut bore” application in the secondrigid pane 4, should it be necessary, in particular if the thickness ofthe pane 4 is rather small, for example less than 5 mm, it would bepossible for this purpose to use, as liner, other suitable components ofthe type already indicated and similar to that of the liner 12 of FIG.2.

The embodiment shown in FIG. 5 combines a connector according to theinvention with a plate element, in which the electrical functionalelements to be connected are on the second rigid pane 4 provided withthe bore 11. Unlike the embodiments described above, in this case nodirect contact is provided between the spring contacts 15 and the planeelectrodes 6 of the heating layer 5. The projection 13 of the liner 12serves instead to keep the connection bridges 20 in contact with theplane electrodes 6 after the liner 12 has been inserted into the bore 11of the rigid pane 4 and fastened therein. Since the liner may be clampedwith the connection box 8 and therefore the projection 13 is pulled witha prestress against the plane electrodes 6, this contact point is notparticularly critical. The surfaces of the connection bridges cominginto contact with the plane electrodes may be roughened or provided withspikes so as to allow slight penetration of the connection bridges intothe plane electrodes. However, in this case it is also possible, asalready mentioned above, to carry out a soldering operation by supplyingheat, after the connection bridges and/or the plane electrodes have beenpretinned.

The ends of the connection bridges 20 on the opposite side from theplane electrodes 6 penetrate the internal space of the liner 12. At thispoint they form, in a manner equivalent to the plane electrodes of theprevious applications, bearing faces for the spring contacts 15 in sucha way that, after mounting, they are electrically connected in areliable manner by means of a respective connection bridge 20 to therespective actual plane electrodes 6.

The connection bridges 20 are preferably securely incorporated into theliner 12, so as to configure as simply as possible the mounting of theconnector. This may, for example, be obtained by overmolding theconnection bridges 20 (thin strips of sheet) with the plastic of theliner 12 as it is being formed.

FIG. 5 again shows the line of separation 7 between the two poles of theheating layer 5 and the opaque layer 10, on which the heating layer isdeposited in each case in the contact region. As a complement, anotheropaque layer 10′ is in this case also provided on the flat side of therigid pane 2 lying inside the composite, which optically covers thecontact region and may be furthermore produced in the form of adecorative element. It is possible, depending on the requirements, tochoose also to omit one or both opaque layers, as these are notimportant for the operation of the connector or of the plate element.

Whereas the adhesive interlayer 3 is continuous in the contact region inthis illustration, it may, again also if required, be provided in thisvariant with a cutout in a manner similar to FIGS. 3 and 4.

In FIG. 5, no temperature probe has, admittedly, been illustrated, butit will be understood that a suitable detection element for detectingthe actual temperature in the connection region may also be provided inthis embodiment variant. It will be conceivable, for example, to producean additional thermal probe in a manner similar to the connectionbridges 20 illustrated here and to bring it into contact with theheating layer or a plane electrode.

When this connector is used for electrical functional elements of othertypes, for example for thin-film solar cells or for impact orprecipitation probes, as indicated at the beginning, its basic structureis not modified from that of the embodiment examples shown here. Bydeparting from the drawings, it is possible to provide only a singlecontact or a plurality of contacts in each cutout.

1-23. (canceled)
 24. A connector for a flat multilayer elementcomprising: a first rigid glazing pane provided with one or moreelectrical functional elements; a second rigid glazing pane joined flatto that side of the first rigid glazing pane that is provided with theone or more functional elements, the second rigid pane having at leastone cutout for making an electrical connection to the one or morefunctional elements; and a liner fastened in the cutout by a projection,an edge of the projection lying in a plane between the first and secondrigid panes and/or catches, via a rear, on an undercut of the cutout,and wherein the liner serves as a counterbearing surface for fasteningat least one connection piece electrically connected to the one or morefunctional elements.
 25. The connector as claimed in claim 24, whereinthe cutout is provided in the first rigid pane having the one or morefunctional elements or in the second rigid pane.
 26. The connector asclaimed in claim 24, wherein at least two regions of the one or morefunctional elements are of different polarity and are brought into aregion of the cutout, and wherein each of the at least two regions isbrought into electrical contact with a connection piece fastened to theliner.
 27. The connector as claimed in claim 26, wherein each connectionpiece comprises at least one spring contact brought into electricalcontact with a respective of the one or more functional elements. 28.The connector as claimed in claim 26, wherein a flat electrode of theone or more functional elements, electrically connected to eachconnection piece, is provided in a region of each connection piece. 29.The connector as claimed in claim 24, wherein the liner is configured ina form of a bush and is inserted into the cutout, its projectioncatching, via the rear, on the edge of the cutout in a plane of aninterlayer.
 30. The connector as claimed in claim 24, wherein theprojection of the liner is provided with at least one contact configuredto make an electrical connection between at least one connection pieceand at least one of the one or more functional elements, this at leastone functional element being associated with the second rigid pane inthe cutout of which the liner is placed.
 31. The connector as claimed inclaim 30, wherein the at least one contact is produced as a connectionbridge that has, in an internal space of the liner in a form of a bush,a contact surface for a connection piece and, on one face of theprojection, a contact surface for connection to a respective of the oneor more functional elements.
 32. The connector as claimed in claim 24,wherein the liner comprises a peg or an undercut-engaging peg that isfastened in the cutout by a screw.
 33. The connector as claimed in claim32, wherein the screw is configured as a bush screw with an externalthread, its internal space forming a housing for other components of theconnector.
 34. The connector as claimed in claim 24, further comprisingmeans for fastening or suspending a flat of the one or more functionalelements in a subjacent structure or a wall of a building.
 35. Theconnector as claimed in claim 24, wherein a flat element is provided asthe one or more functional elements with an electrically conductivecoating of a heating layer.
 36. The connector as claimed in claim 35,further comprising a temperature probe for detecting an actualtemperature of the heating layer.
 37. The connector as claimed in claim36, further comprising a switching element configured to be controlledby the temperature probe, to interrupt or reduce heating current shoulda predetermined temperature threshold be exceeded.
 38. The connector asclaimed in claim 35, further comprising a manually actuated adjustmentdevice for introducing a temperature threshold for the heating layer.39. The connector as claimed in claim 35, as a receiver configured toreceive control signals transmitted without any contact and as aswitching device configured to be controlled by the receiver, forremotely connecting and disconnecting the heating layer.
 40. Theconnector as claimed in claim 24, further comprising at least onedisplay element or a light signal displaying a state of operation of theone or more functional elements.
 41. The connector as claimed in claim24, further comprising a connection box in a form of a casing acting asa cover with respect to external environment.
 42. A flat element withelectrical functional elements incorporated between two rigid plates andat least one connector as claimed in claim
 24. 43. The flat element asclaimed in claim 42, wherein one rigid plate is a pane coated with anelectrically conductive coating.
 44. The flat element as claimed inclaim 42, wherein an optical mask is provided at least in a region ofthe cutout or of the connector on that side not facing the cutout. 45.The flat element as claimed in claim 42, wherein at least one electrodeconfigured to make electrical contact between the electrical functionalelement and the connector is placed on one of the two rigid panes in aregion of the connector.
 46. The flat element as claimed in claim 42,including at least one display element configured to display anoperating state of the one or more functional elements.